Question

How does the passage develop the central idea "Elizabethans believed that health depended on the balance of the four humors"?

Answer 1

This would be the answer to your question:

The passage explains how Elizabethans believed that divine intervention caused imbalanced humors.

Hope this helps. 

Answer 2

How does the passage develop the central idea "Elizabethans believed that health depended on the balance of the four humors"?

The correct answer is:
It explains that Elizabethans believed that divine intervention caused imbalanced humors.

I hope this helps a lot to you.